something matt wrote about how much better search is when it's clued up to context a bit more reminded me of something on amazon.com during the enormous binge I had yesterday. On upmystreet.com we carry the postcode across the tabs - it's the same key being used to tap into different verticals of data. It seemed a bit of an odd idea at first, but I think it's becoming a standard UI metaphor. Certainly yesterday, the fact that amazon dropped whatever your query was whenever I switched tabs was tedious.